What is the difference in 1st AC 2nd & 3rd AC in Indian Railway

1)First Class AC -Is the most expensive and luxurious accommodation that the Indian Railway offers. The berths will limited to each compartment having only 2 or 4 berths the coach will be a divided into coupes and cabins each having a door which can be locked from inside.A cabin has 4 berth 2 on each side The coupe will be smaller than the cabin and only has 2 berth. Each coach has 24 berth with 4 berths with 4 cabin and 4 coupes the first class AC doesn't have the side berth. Plows sheets and blankets are still complimentary.  

2)Second Class AC- Is usually a good compromise between amenities and cost. This coach only has 4 berths in the each coupe and the coach has 48 berth in total. There are only 2 berth in the aisle bay. However,the compartments do not have lockable doors at all,instead they have curtains for privacy Pillows, sheets and blackest are still complimentary. 

3)Three Tier Or Third Class AC- Provide the basic amenities still more than the non AC, but at a more affordable rate. The coach , but is provide with similar to the Sleeper coach, but is provide with AC. There are no curtains or door for privacy.it does not have indiviual reading light.Pillows, Sheets and blanket are still complimentary,food is not complimentary The coach has 64 berth in the coupe, and 2 in the aisle bay.